This invention relates to a dust cap for a fluid coupling, and, more particularly, to a dust cap for a quick disconnect coupling which prevents contamination from entering the coupling when the coupling is connected to another coupling or disconnected and which collects fluid spillage during uncoupling.
Quick disconnect couplings are used, for example, to connect hydraulic fluid line hoses. When the male and female couplings on the ends of a pair of hoses are connected, fluid can flow through the hoses. When the couplings are disconnected, valves within the couplings close and prevent fluid from escaping.
Quick disconnect couplings are so named because the male and female couplings can be quickly connected and disconnected by simple pushing and pulling forces. Such couplings are commonly used, for example, on agricultural tractors for connecting the tractor hydraulic system with the attachable implements.
Quick disconnect couplings are typically located where harmful contamination can enter the hydraulic system and cause damage to system components. When the coupling is disconnected, contamination collects on the oily interfaces. When the coupling is reconnected, the contamination is ingested into the hydraulic system. In dusty environments, such as farming and construction sites, contamination sifts into the parts of the coupling sliding surface and the locking mechanism and can cause malfunction.
Typical protective devices which have been used on quick disconnect couplings are slip-on or snap-on caps and plugs to protect the uncoupled coupling half. However, operators frequently fail to install the caps and plugs, and contamination enters. Also, traditional caps and plugs become oily and collect dust and dirt. Then, when the operator install the cap or plug, it ingests contamination into the coupling halves and into the system.
The inventive cap is attached to the female half of the coupling and automatically closes and seals the uncoupled female half. When a male half is connected to the female half, the male half is inserted through a slit in the cap. The cap wires the male half clean as it is inserted, and the cap seals around the male half to prevent contamination from entering. The cap is provided with a stress relief opening at each end of the slit, and the stress relief openings are covered by flexible and resilient flaps which also assist in wiping the male half during insertion. The cap is provided with a drain port to allow collecting and remote draining of oil which is normally spilled during the disconnecting cycle.